Contact terminal for rectifier plates



Sept. 5, 1939. c. c. 'HE'IN 2 2,172,200

CONTACT TERMINAL FOR RECTIFIER PLATES Filed June 8, 1938 5prayedMeI%//3/7/6 23 la per-041226 VIIIII' ci'l."......l

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ATTORN Patented Sept. 5, 1939 My invention relates to especially contactrectifiers An object of my fective contact terminals rectifier plateswhic CONTACT TERMNAL FOR PLATES Carl C. Hein, Forest Hi1 ManufacturingCompany iughouse Electric & East Pittsburgh, Pa., sylvania RECTIFIER ls,Pa., assignor to Westa' corporation of Penn- Application June 8, 1938,Serial No. 212,442

4 Claims.

contact rectifiers and of large size.

inventionis to provide effor large-size contact.

h will not interfere to any extent with the cooling of the rectifier.

Other objects and will be apparent fro and drawing, in which:

advantages of the invention m Figure-1 is a top plan view of a preferredembodiment of my invention;

Fig. 2 is a side elevationalfview of the device of Fig. 1;

Fig. 3 is an enlarged cross sectional view taken 15 on the line 1n m ofFig. 1;

Fig. 4 is an enlarged cross sectional view taken on the line IVIV o Fig.5 is a top plan view;

6 is a cross sectional view of the one end the contact terminal;

.Figs. 7 and 8 are a top plan view and a cross sectional view of thehorseshoe washer disclosed in cross section in Fig. 3;

Figs. 9 and' 10 are 25 sectional view of the c ntact a semb y the topmetal; eyelet utilized in the and sectional view of the insulatingeyelet utilized'irf the contact assembly.

My invention parti cularly concerns making improved contact terminals tocontact rectifiers having large rectifying rectifiers, especially of thecopper been adapted for various uses amounts of current electroplatingand welding. For heavy current demands, numerous areas. These contactfor various these uses of stacks of large copper plates are utilized andthese plates are constantly cooled by fans when in operation. The

0 individual plates have a large area generally from 30 to 50 squareinches on each side of the plate for the rectifying area. larly concernsmaking a the surface of such My invention particua plate withoutinterfering with the cooling of the plate to any extent. In

Figs. 1 and 2, I have .disciosed a large area copper plate I having acopper oxide rectifying layer It and [2 on each side thereof. Ipreferably coat the oxide layer with a solution of i0 graphite in waterand then spray a metal over the surface to form the graphite solution beused alone, but I a contact layer 13,- Either or the sprayed metal mayprefer the combination of v the two layers as being more satisfactory.The

5 sprayed metal coati ng l3 may be of any low the following descriptionplan view and cross oxide type, have large area contact tomelting alloysuch as one composed of 37 by weightof tin.

At each end of the plate, but preferably symmetrically disposed Withinthe plate, I provide two openings l4 and I5. An insulating eyelet,preferably of fish paper It, particularly disclosed in Figs. 11 and 12,is inserted in the hole It and its flanges bent around the edges of thehole to completely cover the exposed copper part I 0 of the plate. Along thin strip I1, preferably copper, has one end l8 havwhose shape ismore ing an opening therethrough of the same size as the hole It. Thisstrip is placed on the top surface'with its opening coinciding with theopening l4, and a similar strip I1 is placed on the underside of therectifier plate. The other end IQ of the'strip terminates in the tapthat is covered with insulation 2| and this extends to the inner edge ofthe hole IS in the plate. The under strip likewise terminates in aninsulat ing covered tab. This terminal strip is of relatively thinmaterial both for the saving in cost of material and for the reductionof thickness so as to reduce the cross sectional area of the rectifierpresented to the fan or blower used for ventilation. The terminal stripcan also be flexed slightly to exert a slight pressure against the'fspra'yedcoating." The contact area can be relatively large and made toeliminate much of the 'point contact in devices of the prior art. Thecontact strip can be crimped at the edges or center if any strengtheningis desired. At the end having the opening IS, a horseshoe washer 22, asdisclosed in Figs, 7 and 8, is placed around the top and bottom of thehole l 5 in order to hold the .insulation covered tabs 20 in place -Ametal eyelet 23 is then placed in the opening l4, and the bottom .edges24 are peened over to securely bind-the terminal strips IT to the platesat this end. A similar metal eyelet 25 is placed in the opening I5 atthe other end of the plate and its bottom edge 16 is'peened over tosecurelg bind the terminal strips [1 and the horseshoe washer 22 to thecontact rectifier. These metal eyelets are disclosed in their preferredshape in Figs. 9. and- 10.

It will be noted from an examination of Figs. 1

nal strip H by the insulation and also by the absence of the oxideadjacent the opening 55 and makes contact with the copper it which isex-' posed in the central portion of the opening it. The eyelet 25accordingly acts asthe positive contact to the rectifier and the circuitterminal may be secured thereto.

While I have disclosed the invention as applied to a copper oxiderectifier, the invention may be applied to contact rectifiers. of othermaterials. Theparticular advantages of the contact terminals is a largereduction in cost due to the specific design utilizing design issymmetrical both in regard to the mounting holes symmetrically placedand being within the area of the plate with a resulting reduction inoverall volume. The narrow cross sectionalarea of the assembled platewill permit closer spacing of the plates with the further decrease inthe volume occupied by a specific number of plates. The terminal stripis securely fastened to the plate and provides a constancy of contactresistance. If desired, protective coatings can be applied to the entiresurface and edges.

While I have disclosed a preferred embodiment of my invention, it isapparent that many media flcations may be arrangement and location ofthe various elements. Accordingly, I desire only such limitati ons to beimposed upon the following claims as is necessitated by the prior art.

4 I claim as my invention:

1. A contact rectifier comprising a metal plate,

a layer making a rectifying contact with said metal plate on the surfacethereof, said plate very little material. The

made in the particular shape,

} awaaoo 'I'he'metal eyelet 25 is insulated. from the termihaving twospaced openings therethrough, a contact strip extending from one openingto the other, insulation about the metal plate at one opening andinsulation about the strip at the other opening and fastening contactmeans I through said openings, binding said strip, plate and layer.

2. A contact rectiflercomprlsing a. plate. a

the surface of said platecopper omde layer on said. plate having twoopenings therethrough, a contact strip extending from one opening to theother, insulation about the copper plate atone opening, insulation aboutthe strip at the other opening and fastening contact means through saidopenings binding said strip, plate and layer.

3. A contact rectifier comprising a metal plate, a layer making a'rectifying contact withv said metal plate on having two spaced openingstherethrough, a. contact strip extending from one opening to the other,insulation about the metal plate at one opening, insulation about thestrip at the other opening, and an eyelet through each opening bindingsaidstrip, plate and layer together.

i. A contact to a contact rectifier cl! 9. metal and a layer thereoncomprising a flat strip of metal making a broad surface contact to saidlayer, said rectifier having an opening therethrough, the layer-beingabsent from around said opening, said strip extending to said openingand having its end adjacent thereto covered with insulation, ahorseshoewasher making contact with the metal around said opening and holding theend of the strip in place and an eyelet through washer and rn'etaltogether.

. CARL 0. m.

said'opening binding said strip the surface thereof, said plate

